Advanced Devices & Sustainable Energy Laboratory (ADSEL) at VT focuses on novel device architectures and electronic materials for future applications in optoelectronics and quantum electronics. At ADSEL, the research emphasis is on developing strained germanium (Ge)/InGaAs based co-integrated CMOS transistor for "enhancement" and "replacement" in future information processing systems and diverse materials growth for energy efficient nanoelectronics. The strain and bandgap engineered group IV based materials (i.e., Ge, GeSn) and large bandgap III-V compound semiconductors offer a unique combination for electronics and photonics. We are also interested in adding new functionalities on Si chip by investigating the Ge/InGa(Al)As based transistors and a new generation energy-efficient tunnel transistors. In every device architecture, superior device-quality materials with high carrier lifetime, low defect density, abrupt heterointerface, low surface roughness, materials compatibility, and avoiding cross-contamination of atomic species are essential. This can be achieved by establishing novel group III-V and group-IV materials growth capabilities, detailed materials analysis, new device structures to discover new physical mechanisms and innovative materials and device integration strategies for incorporation of different semiconductors and device types onto Si process technology or a common substrate platform.